From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Bruno Wolff III <bruno@wolff.to>
Cc: Josh Boyer <jwboyer@redhat.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"peterz@infradead.org" <peterz@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c
Date: Thu, 17 Jul 2014 01:18:36 +0200 [thread overview]
Message-ID: <53C7084C.7090104@arm.com> (raw)
In-Reply-To: <20140716195414.GA16401@wolff.to>
On 16/07/14 21:54, Bruno Wolff III wrote:
> On Wed, Jul 16, 2014 at 21:17:32 +0200,
> Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
>> Hi Bruno and Josh,
>>
>>From the issue, I see that the machine making trouble is an Xeon (2
>> processors w/ hyper-threading).
>>
>> Could you please share:
>>
>> cat /proc/cpuinfo and
>
> I have attached it to the bug and to this message.
>
>> cat /proc/schedstat (kernel config w/ CONFIG_SCHEDSTATS=y)
>
> It looks like that isn't set for my previous builds and I'll need to
> set it for my next test build.
>
>> Could you also put the two BUG_ON lines into build_sched_groups()
>> [kernel/sched/core.c] wo/ the cpumask_clear() and setting
>> sg->sgc->capacity to 0 and share the possible crash output as well?
>
> I can try a new build with this. I can probably get results back tomorrow
> before I leave for work. The crashes happen too early in the boot process
> for me to easily capture output as text. I can slow things down to take
> pictures though.
>
That would be helpful. Thanks. I saw that you have CONFIG_SCHED_DEBUG
enabled.
So the output of
$ cat /proc/sys/kernel/sched_domain/cpu*/domain*/*
would be handy too.
The difference to the Intel machine I tested on is that yours is a "dual
single core CPU with hyper-threading' and mine is a 'dual core with
hyper-threading'
yours:
$ cat cpuinfo.out | grep '^physical\|^core\|^cpu cores'
physical id : 0
core id : 0
cpu cores : 1
physical id : 3
core id : 0
cpu cores : 1
physical id : 0
core id : 0
cpu cores : 1
physical id : 3
core id : 0
cpu cores : 1
mine:
$ cat /proc/cpuinfo | grep '^physical\|^core\|^cpu cores'
physical id : 0
core id : 0
cpu cores : 2
physical id : 0
core id : 0
cpu cores : 2
physical id : 0
core id : 1
cpu cores : 2
physical id : 0
core id : 1
cpu cores : 2
Just to make sure, you do have 'CONFIG_X86_32=y' and '# CONFIG_NUMA is
not set' in your build?
next prev parent reply other threads:[~2014-07-16 23:18 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-16 14:55 Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c Bruno Wolff III
2014-07-16 15:17 ` Josh Boyer
2014-07-16 19:17 ` Dietmar Eggemann
2014-07-16 19:54 ` Bruno Wolff III
2014-07-16 23:18 ` Dietmar Eggemann [this message]
2014-07-17 3:09 ` Bruno Wolff III
2014-07-17 8:57 ` Dietmar Eggemann
2014-07-17 9:04 ` Peter Zijlstra
2014-07-17 11:23 ` Dietmar Eggemann
2014-07-17 12:35 ` Peter Zijlstra
2014-07-18 5:34 ` Bruno Wolff III
2014-07-18 9:28 ` Dietmar Eggemann
2014-07-18 12:09 ` Bruno Wolff III
2014-07-18 10:16 ` Peter Zijlstra
2014-07-18 13:01 ` Bruno Wolff III
2014-07-18 14:16 ` Dietmar Eggemann
2014-07-18 14:16 ` Peter Zijlstra
2014-07-18 14:50 ` Peter Zijlstra
2014-07-18 16:16 ` Peter Zijlstra
2014-07-21 16:35 ` Bruno Wolff III
2014-07-21 16:52 ` Peter Zijlstra
2014-07-22 9:47 ` Peter Zijlstra
2014-07-22 10:38 ` Peter Zijlstra
2014-07-22 12:10 ` Bruno Wolff III
2014-07-22 13:03 ` Peter Zijlstra
2014-07-22 13:26 ` Peter Zijlstra
2014-07-22 13:35 ` Peter Zijlstra
2014-07-22 14:09 ` Bruno Wolff III
2014-07-22 14:18 ` Peter Zijlstra
2014-07-23 1:37 ` Bruno Wolff III
2014-07-23 6:51 ` Peter Zijlstra
2014-07-22 17:05 ` H. Peter Anvin
2014-07-23 15:11 ` Peter Zijlstra
2014-07-23 15:12 ` H. Peter Anvin
2014-07-24 1:45 ` Bruno Wolff III
2014-07-23 15:39 ` [tip:x86/urgent] x86, cpu: Fix cache topology for early P4-SMT tip-bot for Peter Zijlstra
2014-07-22 12:12 ` Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c Dietmar Eggemann
2014-07-22 12:57 ` Bruno Wolff III
2014-07-28 8:28 ` [tip:sched/core] sched: Robustify topology setup tip-bot for Peter Zijlstra
2014-07-17 16:36 ` Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c Bruno Wolff III
2014-07-17 18:43 ` Dietmar Eggemann
2014-07-17 18:54 ` Bruno Wolff III
2014-07-17 4:21 ` Bruno Wolff III
2014-07-17 4:28 ` Bruno Wolff III
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